Install Prot-On app and log-in with your free Prot-On account username

Download link: https://appworld.blackberry.com/webstore/content/59937563/?lang=en

 Select the file you want and you will get following screen. Tap "Save"

 File will down load

 

 Tap and hold the download in the list and a menu will come up. Select "Open in" like in following image

 Select "Prot-On"